[Craving] is like someone who is extremely hungry. Such a person doesn’t actually think in terms of eating the food, chewing it and swallowing it. Instead the food just goes into his stomach. It’s very simple, there’s no effort involved, it just goes into him… Craving in this case is not so much what the weightwatcher’s club talks about, but it’s genuine craving. It actually just happens. We could actually say to somebody literally, “I don’t know what happened, I just did it. It just happened to me. It just happens to me constantly.” … So it’s instant craving, rather than deliberate craving as such. At that level, there’s no intellectualization at all involved.
Taṇhā encompasses both the desire to get something and its opposite, the desire to get rid of it.
Ron Leifer states:
…taṇhā itself is bipolar, divided into greed and hatred, or passion and aggression. On the one hand is the desire to have something, to possess it, to experience it, to pull it in, to own it. On the other hand is the desire to avoid something, to keep it away, reject it, renounce it, destroy it, and separate it from oneself. If we call these two poles desire and aversion, we can see more clearly that they represent the antithetical poles of taṇhā–the desire to possess and the desire to get rid of.
Unsatisfactory, unquenchable, addictive
Taṇhā is represented in the bhavacakra by a group of people drinking beer or partying.
Ron Leifer states:
Desire [i.e. taṇhā] causes suffering by its own nature because it is inherently unsatisfactory. Desire means deprivation. To want something is to lack it, to be deprived of it. We do not want things we have, we only want things we don’t have. Thirst is the desire for water and it occurs in the absence of water. Hunger is the feeling of lacking food. Desiring means not having, being frustrated, suffering. Craving is suffering. This is a most important insight, one which we drive into secrecy by our refusal to acknowledge it, thus creating the esoteric knowledge we then seek.
Most people tend to act under the assumption that if one’s desires are fulfilled it will, of itself, lead to lasting happiness or well-being.
[NB] However, the Buddhist teachings state that desire for conditioned things cannot be fully satiated or satisfied, due to their impermanent nature.
This is expounded in the Buddhist teaching of impermanence.